Since hydrogen storage materials have properties similar to those of gasoline, some of the existing infrastructures for petroleum fuels can be used for them and also since their explodability is lower than other hydrogen fuels, they are hydrogen fuels which can be supplied at low cost with safety. However, one feature of hydrogen storage materials is that they generate not only hydrogen but also dehydrogenation product by dehydrogenation. The dehydrogenation product can be reused by repeating hydrogenation and dehydrogenation and it is expected that the cost of hydrogen storage material supply is reduced by taking advantage of this. Therefore, the user of a hydrogen storage material must recover the dehydrogenation product derived from hydrogen generation. One recovery method is that a partition is provided in the fuel tank as disclosed in JP-A No. 2004-250059 (hereinafter referred to as Patent Document 1)    Patent Document 1: JP-A No. 2004-250059